Lab 2- TLC
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Experiment #2
Thin Layer Chromatography
Lab Partner – Teaching Assistant – Date Performed – October 5, 2023
Date Due - October 12, 2023
Experimental Objective
Thin layer chromatography (TLC) is performed in the first stage of the experiment to determine which solvent is best for separating aspirin, acetaminophen, and caffeine. Subsequently, the components of a combination are identified using TLC and the specified solvent.
Procedure
Setting up the TLC plates and determining the better solvent
One centimeter down from the TLC plate's bottom, a horizontal line was drawn. From this line, vertical lines were drawn to show the locations of the samples (aspirin, acetaminophen, and caffeine). After that, the samples were moved via the capillary tubes onto the TLC plate. The sample size was intended to be as small as a tiny dot because any larger or smaller would have distorted the findings. For comparison, two solvents were used: 1:1 Hexanes:Ethyl Acetate and 95% ethyl acetate with 5% acetic acid. The TLC jars received around 3 mL of solvent poured to them. Subsequently, the plates were inserted into their corresponding jars, with the upper part of each plate resting on the jar. The solvent was about 1 cm from the top when the plate was taken out. Where the solvent ceased was marked on the plate.
The spots on the TLC plate were visible using the short wave UV section. To find the Rf values, the spots were lightly drawn with a pencil. We compared the two plates to see which solvent would produce the best outcomes. Since the samples separated, 95% ethyl acetate and 5% acetic acid seemed to be the best solvent. Working unknown sample #247
In a test tube, about 28 mg of unknown #247 were dissolved in 1 milliliter of 95% ethanol. The unknown solution was made and spotted on a second TLC plate. A ruler was used to measure from the beginning line to the center of each sample dot after all of the plates had been produced.
The sample's Rf values were ascertained using the dots. To ascertain which compounds made up unknown #247, the values of the unknown and the known substances were compared.
Results
Figure 1:
Drawn depictions of all 3 TLC plates involved
The below equation was used to calculate the Rf values for all spots on all plates, given the dimensions and measurements of the observed plates which are pictured above. The measurements and calculated data are shown in the below tables.
Table 1:
Data from TLC plates in 1:1 Hexanes:Ethyl acetate
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Related Questions
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Column Chromatography
Alumina
Chromatography Mixture
9:1 Hexanes:Ether
8:2 Hexanes:Ether
1:1 Hexanes:Acetone
Amount Used
3.962 g
0.143 g
9.50 mL
9.50 mL
11.00 mL
Additional Observations (Color, etc.)
BIU X₂ X² →
BI IU X₂ X² →
BI IU X₂ X² →
BI IU X₂ X² →
BIU X₂ X² →
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4 Essential oils
Alcohols
b) Volatile compounds
d) Non-volatile compounds
13-
is measured as time elapsed from the point of injection to the peak maximum?
a)-Column efficiency d)- Delectability
c)-Retention time
14- Which of the following can be used to detect the components in gas chromatography
a) non-volatile compounds b) volatile compounds
c) Salts
d) b&c
15-Which of the following methods is often referred to as mechanical separation processes.
a)-Gas Chromatography b)-column chromatography c)- Sedimentation
16- For obtaining better resolution in TLC.
and then developed with a second solvent at right angles to the first
a) Stepwise b) Descending e) Ascending
17- This is defined as transport of electrically charged particles in a direct-current electric field
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d) exclusion
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C) 300ml D) 400ml
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Thin-layer chromatography (TLC)
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MW Standards
Molecular Weight (kDa)
Elution Volume (mL)
blue dextran
1000
85
myoglobin
17.2
200
TIM
53.3
178
hemoglobin
62.2
156
IgG
140
122
ATCase
307.9
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Compound Structure
Compound
Name
Elution Order (1-6)
Non polar → Polar
Boiling
Retention Time
(From Chromatograms)
Point
Propyl
acetate
H
H.
H.
Butyl
acetate
H.
H.
H
H.
H
H.
H.
H.
Methanol
H
O-
Ethanol
2-butanone
H H
H.
H.
4-methyl-2-
pentanone
H.
H.
HH
H.
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1. chromatography" derived
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"graphein" meaning to write.
The stationary phase
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supported on a solid or gel.
3. The mobile phase may be
2.
Solid.
4. Silica gel is the most
common stationary phase in
adsorption chromatography.
5. Liquid Chromatography
abbreviated as (GC ).
6. In Thin Layer
Chromatography, the mobile
phase is gas.
7. a = KB/KA, where Kg is the
distribution constant.
8. k'B and k'A are the retention
factors.
9. Rf, is the distance traveled
by the compound ONLY.
10. Chromatography is a
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%3!
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0.5
Relative peak area
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2.5
15.03
3.5
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25.33
5.5
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Peak
Retention time (min) | Width of peak base (min)
non-retained
2.1
A
6.4
10.51
B
11.3
1.03
C
13.1
1.25
D
21.6
1.62
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soon after adding the Fe" solution from a buret.
TABLE 1
Fe
5 ml
5S mL
Solution
Distilled Water
CNS
2 mL
Total Volume
3 ml
2 ml
10 ml
3 mL
10 ml
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following circumstances:
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5) Determine the melting point of the product
U 6) Put an astronaut on the moon.
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Related Questions
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- EBK A SMALL SCALE APPROACH TO ORGANIC LChemistryISBN:9781305446021Author:LampmanPublisher:CENGAGE LEARNING - CONSIGNMENT
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ISBN:9781305446021
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